The invention relates to sealing elements in general, and more particularly to improvements in sealing elements of the type often utilized in apparatus for testing plain or filter cigarettes or other rod-shaped articles of the tobacco processing industry with a fluid medium. Apparatus which can utilize sealing elements of the present invention are disclosed, for example, in U.S. Pat. No. 3,948,084 granted Apr. 6, 1976 to Heitmann et al. The disclosure of this patent is incorporated herein by reference.
Successive rod-shaped articles of the tobacco processing industry are normally tested with a fluid, such as air, which is admitted (e.g., drawn) through one end of a rod-shaped article (hereinafter called cigarette for short) and is evacuated through the other end or escapes through one or more holes in the tubular wrapper, through an open seam of the wrapper, at the frayed ends of the wrapper and/or through an overly porous wrapper of a defective article. Uncontrolled escape of testing fluid from the path between the two ends of a cigarette is detected by suitable monitoring means having means for generating signals which are used to segregate defective articles from satisfactory articles and/or to carry out adjustments which are necessary to cease the making of defective articles.
Heretofore known sealing elements which are utilized in cigarette testing apparatus (e.g., in apparatus of the type disclosed in the patent to Heitmann et al.) are normally made of an elastomeric material and resemble or constitute tubular bodies with readily deformable apertured end walls which are moved into abutment with end faces of cigarettes to be tested preparatory to causing a testing fluid to flow from a sealing element into the adjacent end portion of a cigarette or in the opposite direction.
A drawback of presently known sealing elements is that they are likely to gather fragments of tobacco and/or filter material for tobacco smoke. The thus gathered particles can interfere with the flow of testing fluid so that a defective cigarette is likely to be classified as a satisfactory product or that a satisfactory cigarette is segregated from other satisfactory cigarettes because the testing of the satisfactory cigarette resulted in the generation of signals denoting defective cigarettes.